Tool-holder.



PATENTED SEPT. 27, 1904.

J. HUNTER.

TOOL HOLDER.

APPLICATION FILED 001129, 1901.

N0 MODEL.

X/W M/Aa Patented September 27, 1904.

JAMES HUNTER, OF HARTFORD, CONNECTICUT.

TOOL-HOLDER.

SPECIFICATION forming part of Letters Patent No. 770,966, dated September 27, 1904. Application filed October 29, 1901. Serial No- 80,419. (No model.)

1" 0 @ZZ whom it may concern.-

Be it known that 1, J AMES HUNTER, a citizen of the United States, and a resident of Hartford, in the county of Hartford and State of Connecticut, have invented certain new and useful Improvements in Tool Holders, of which the following is a full, clear, and exact description, whereby any one skilled in the art may make and use the same.

This invention relates particularly to an apparatus for holding thread-cutting dies or taps of the kind specified, having features of novelty and advantage.

In the drawings, Figure 1 is a side view of the device, partly in section, showing the parts in their original position before beginning to cut the thread. Fig. 2 is a front end view of the device. Fig. 3 is a sectional end view of the body part. Fig. 4 is an end view of the die-holder member. Fig. 5 is a side view of the device, partly in section, showing the forward position of the parts after the thread has been cut. Fig. 6 is an end view, partly in section, showing the position and direction of movement of the die-holder proper before the machine is reversed. Fig. '7 is a view similar to Fig. 6, showing the position of the dieholder as it is ready to travel back to its original position, the machine being reversed. Fig. 8 is a side view, partly in section, showing the die-holder returned to its original position after the thread has been out.

My device is in general the same as the toolholders which have been commonly used in machines of this class, comprising what may be termed the body portion, which is secured in place in the turret, and the die-holer proper, which is mounted in and capable of lengthwise movement relative to the body portion. This invention has to do particularly with the feeding or moving of the die-holder proper forward and backward for adjusting the length of the thread to be out. In the following description it will be assumed and in the drawings the device is shown as holding a die to cut a thread on a blank, such as a screw or bolt. The Well-known turret and operating mechanism therefore is omitted as not forming a part of the invention.

In the drawings, A denotes the body part,

having a reduced shank, by which it is supported in the turret. In the first eight figures of the drawings this body is shown with two grooves B, formed lengthwise along its interior face. On the outside of the body supported in suitable manner is a double-ended pawl C, projecting through the shell of the body. The left-hand end of this pawl 0 is beveled, and the right end 0 is square. The interior surface of the body is also grooved circumferentially near one end, as at D, this groove being coincident with the slot through the wall of the body in which the pawl C moves. The squared end 0' of the pawl 0 when it is pressed down is coincident with one side of one of the lengthwise grooves B and obstructs the circumferential grooves D.

The die-holder proper is of the ordinary construction having a recess for the die and means, such as a screw, for holding the die in place and a reduced shank which passes through the shank on the body part and projects beyond it. At the end of the shank of the die-holder is a collar (Z, which limits the movement of the forward travel of the dieholder through the body. Projecting radially from the outer surface of the die-holder are two lugs E E, adapted to move in the lengthwise grooves B B in the body part.

The operation of the device is in general the same as in ordinary screw-machines and in detail is as follows: The die in the die-holder is presented to the blank which is to be operated upon and which rotates, the die-holder occupying the position in the body part which is shown in Fig. l of the drawings, the lugs E on the die-holder located in the lengthwise grooves in the body. When the die is brought into contact with the blank, it of course begins to cut a thread, the die-holder being held against rotary movement by the lugs E and the grooves B. The die-holder is, however, free to move lengthwise of the body part, and this it will do under the influence of the thread which is being cut on the blank, and it will continue to move forward until the lugs come into the path of the circumferential groove D. At this time the cutting of the thread ceases. The die-holder is free to continue the rotation in this direction until the machine reverses, the left-hand end 0 of the pawl being beveled to permit the lugs E E to pass under it, throwing the opposite end a down to be raised as the lugs pass under it. When the machine reverses, the die-holder will turn backward with it until one of the lugs come in contact with the squared end 0' of the pawl. Further rotation of the die-holder is now in1- possible, and under the influence of the thread which has been cut the die-holder is driven back into the body part, the lugs E E traveling back in the grooves B B.

Projecting through the rear walls of the body are screws F E, which limit the inward movement of the die-holder. By means of these screws the length of the thread to be out can be adjusted to any desired degree, and the tool can be made to cut a single thread or a dozen or more by simply changing the adjustment of these screws.

I have shown and described herein two forms of this invention; but it is clear that many other modifications may be made operating in the same manner and for the same purposes without departing from the spirit of my invention, and I wish to cover herein and by the following claims any and all such modifications. It is also evident that this device can be used for holding a tap as well as for holding a thread-cutting die, and I wish it to be understood that I intend to cover herein, and in the following claims the use of this tool-holder for thread-cutting and analogous uses. It should also be understood that this tool can be used for cutting left as well as right hand threads by simply reversing the position of the double-ended pawl C.

In my application filed May 12, 1903, se rially numbered 156,848, there are illustrated other embodiments of an invention of this same general character.

I claim as my invention- 1. In a device of the class specified the body, a groove formed in its interior surface and lengthwise thereof, said groove opening into a circumferential groove near the end of said body, said circumferential groove, a holder adapted to move lengthwise of said body, a lug on said holder adapted to move in said lengthwise groove, and meanslocated in said circumferential groove for preventing the rotation of said die-holder in one direction.

2. In a device of the class specified the body, a lengthwise groove in the interior surface thereof, and a circumferential groove near one end of the body into which said lengthwise groove opens, a pawl mounted on said body and projecting into said circumferential groove, a die holder adapted to move lengthwise of said body, and a lug on said die-holder moving in the groove and preventing a relative rotation of the parts until said lug comes into the path of said circumferential groove, at which time said die-holder is capable of movement in one direction with respect to the body,substantially as described.

3. In a device of the class specified the body, lengthwise grooves arranged interiorly lengthwise thereof, a circumferential groove near one end of the body into which said lengthwise grooves open, a double-ended pawl pivoted on said body so that when either end is depressed it will enter said circumferential groove, one end of said pawl being cam-shaped and the other forming a stop which is located adjacent to one of said lengthwise grooves, and a die-holder having lugs adapted to cooperate with said lengthwise and circumferential grooves, substantially as described and for the purposes set forth.

JAMES HUNTER.

Witnesses:

D. I. KREMUNDAHL, M. H. DERBY. 

